Overview of Text Queries

The basic interMedia Text query takes a query expression, usually a word with or without operators, as input. Oracle returns all documents (previously indexed) that contain that satisfy the expression along with a relevance score for each document. Scores can be used to order the documents in the result set.

A Text query can include one or more CONTAINS clauses and one or more structured clauses.

The basic Text query has not changed for 8.1.

Text Query Expressions

Apart from a few operators (discussed in this chapter) that are no longer supported, the basic Text query expression syntax in 8.1 (everything between the single quotes) is the same as in pre-8.1.

Text Query Methods

In pre-8.1, the system enabled you to execute queries using one of three methods, namely the one-step, two-step, or cursor query, formerly known as an in-memory query.

In 8.1, Oracle no longer supports the two-step method that uses the PL/SQL CONTAINS procedure followed by a join on the result and base table. The two-step query functionality is available through the new Text query which uses the SELECT statement.

In 8.1, the only query method is the standard SQL SELECT statement in which you use the CONTAINS operator in the WHERE clause. As this query is standard SQL, you can use it programatically wherever you can use the SELECT statement, such as in PL/SQL cursors.